Formation of sedimentary structures in flume experiments under upper-flow-regime conditions

上部流态条件下水槽实验中沉积结构的形成

• 批准号: 08640565
• 负责人: YAGISHITA Koji
• 金额: $ 0.96万
• 依托单位: Department of Geoiogy, Faculty of Education, Iwate University.
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640565/
• 关键词: plane beds; flume experiments; upper-flow-regime; imbrication; detrital grains; Froude Number; ripples; low-relief bedform; formational process; critical flow.; 掃流力; 無次元掃流力; 粒子配列; 堆積構造; リップル

In an attempt to produce plane beds under upper-flow-regime conditions, we have conducted a number of runs (experiments) using a hydraulic flume of 15 cm wide and 700 cm long, at the Ocean Research Institute, University of Tokyo. We have succeeeded in producing two types of plane beds : 1) laminae formed and buried by the migration of low-relief asymmetric ripples under near- or sub-critical flow (Froude Number Fr=0.94 ; type 1), and 2) laminae formed without causing any low-relief bedform but under super-critical flow (Fr=1.98 ; type 2). After making these two types of plane beds, imbrication of detrital grains along each plane bed was investigated. The sediments of sand-sized quartz grains (mean diameter 0.72 mm) show a high angle of imbrication (up to 30ﾟ) in type 2, whereas very low angle of imbrication (close to 0ﾟ) in type 1. Differences of imbrication angle between the two types of plane bed may be useful to infer the individual formational process of plane beds that are observed in the field.

为了在上游流态条件下产生平面床，我们在东京大学海洋研究所使用15 cm宽、700 cm长的水力水槽进行了多次试验。我们已经成功地生产了两种类型的平面床：1）在近或亚临界流（Fr=0.94 ;类型1）和2）在没有造成任何低起伏的底形，但在超临界流（Fr=1.98 ;类型2）的纹层的低起伏不对称波纹的迁移形成和掩埋。在这两种类型的平面层，碎屑颗粒沿沿着每个平面层的叠瓦作用进行了研究。类型2的砂级石英颗粒（平均直径0.72 mm）沉积物呈高叠瓦角（高达30 °），而类型1的叠瓦角很低（接近0 °）。两种类型的平面层之间的叠瓦角差异可能有助于推断野外观察到的平面层的个体形成过程。

项目成果

YAGISHITA,K., ASHI,J., NINOMIYA,S.& TAIRA,A.: "Plane beds in flumes under upper-flow-regime conditions." Annual Meeting of Sedimentological Society of Japan (at Shizuoka Univ.) Abstract. 79-80 (1997)

八木下,K., ASHI,J., 二宫,S.

八木下晃司・芦寿一郎・二宮悟・平朝彦: "水槽実験による高い流れ領域での平坦ラミナの形成について-予報-" 地学雑誌. 106巻・第3号. 356-363 (1997)

Koji Yagishita、Juichiro Ashi、Satoru Ninomiya 和 Asahiko Taira：“通过水箱实验研究高流量区域中的平坦纹层的形成 - 预测 -”地质杂志，第 106 卷，第 3 期。356-363 (1997)

YAGISHITA,K., ASHI,J., NINOMIYA,S.& TAIRA,A.: "A preliminary report on experimental plane beds under upper-flow-regime conditions" Journal of Geography. v.106. 356-363 (1997)

八木下,K., ASHI,J., 二宫,S.

八木下 晃司・芦 寿一郎・二宮 懐・平 朝彦: "水槽実験による高い流れ領域での平坦ラミナの形成について-予報-" 地学雑誌. 106巻・第3号. 356-363 (1997)

Koji Yagishita、Juichiro Ashi、Kai Ninomiya 和 Asahiko Taira：“通过水箱实验在高流量区域形成平坦层 - 预测 -”地质杂志，第 106 卷，第 3 期。356-363 (1997)

八木下晃司・芦寿一郎・二宮悟・平朝彦: "水槽実験による高い流れ領域での平坦ラミナの形成について-予報-" 地学雑誌. 106巻3号. (1997)

Koji Yagishita、Juichiro Ashi、Satoru Ninomiya 和 Asahiko Taira：“通过水箱实验形成高流量区域的平坦纹层 - 预测 -”地质杂志第 106 卷，第 3 期（1997 年）。